A solar energy farm set to rise in Ramona is generating widespread opposition from residents who say it’s too close to their homes and will disrupt bucolic valley scenery.

The issue goes before the county Board of Supervisors Wednesday morning, and its decision may set the benchmark for siting large solar panel facilities in semi-rural areas rather than desert locales.

The proposal from Sol Orchard, LLC calls for 43 acres of rotating panels on a 110-acre site at 1650 Warnock Road.

The Carmel-based company has approval from county planners for the major use permit needed to build the roughly $20 million facility. But that’s being challenged by two community groups and an environmental law firm representing construction laborers.

Sol Orchard’s proposal also is being watched because supervisors and other local elected officials increasingly encourage development of solar power generation, including installation of panels on commercial and residential rooftops.

A similarly sized solar array being built by Sol Orchard in Valley Center also won approval from county planners. An appeal of that project’s permit was dropped and thus never went before the supervisors.

How they respond to Ramona’s concerns, which center around location and aesthetics such as view disruption and site screening, could signal what will be allowed in unincorporated areas that have a significant population such as Ramona, home to about 40,000 people.

“This is a solar factory being put in the middle of the community and close to half of our residents,” said Jim Piva, chairman of the Ramona Community Planning Group, which opposes the project. “It’s the least optimal spot, and that’s where the beef is.”

Sol Orchard has two other projects in the county permit pipeline, a five-megawatt facility in Boulevard and a two-megawatt proposal in Alpine.

The company has a deal with San Diego Gas & Electric to buy the power, and the 7.5 megawatts the Ramona project would generate is enough to provide the power needs of several thousand homes.

Chris Brown, a land-use consultant working with Sol Orchard, said location is crucial.

“They need to be near a substation and have access to feeder (electrical) lines,” he said. “The other thing is that wherever they are built is where the power stays. The electricity this produces stays within Ramona.”

The panels range from 8 to 11.5 feet in height and would face east in the morning and west in the afternoon.

The Ramona planning group, an advisory body to the county, voted 8-0 against the project in May. Members concluded the solar farm’s size was incompatible with the neighborhood, takes away prime farmland and would be a “blight” on the area.

The county does not have a solar power ordinance specifying where such facilities should be located. Instead, its regulations allow solar farms on agriculturally zoned lands if the builder obtains a major use permit, which lays down a wide array of conditions.

Piva said lack of a solar siting policy is another aspect of his group’s concerns.

“The county has not been clear on its standards,” he said. “And this one is just being shoved down our throats.”

Another group known as Citizens for a Rural Ramona contends the landscaping plans around the site to screen it from view are inadequate.

Richard Drury represents the Laborers’ International Union of North America Local No. 89, which also has filed an appeal. Drury is a principal in an environmental law firm, which argues the project needs a full-scale environmental impact report. County planners say it meets all environmental regulations and no such report is required.

The laborers’ union has intervened in the permit process in other solar panel projects around the country. While focusing its opposition on environmental issues, it has also cited the few workers per acre the projects require and how those lands are removed for other job-producing purposes.

“There’s no question we need alternative energy, but in the right places and under the right conditions,” Drury said.

In addition Sol Orchard’s Ramona, Valley Center, Alpine and Boulevard projects, the county has three others in the pipeline, including a second one in Boulevard that would cover more than 400 acres.

Two years ago, supervisors approved two other solar large solar energy farms, both in Borrego Springs and each encompassing more than 300 acres.

The Ramona hearing at 9 a.m. Wednesday at the County Administration Center in downtown San Diego.